Caralluma europaea
| Light | Bright light to full sun; a little shade in the hottest summer months |
|---|---|
| Water | Sparingly in growth; keep nearly dry through the cool winter rest |
| Soil | Very free-draining, gritty mineral mix (see Soil and potting mix) |
| Temperature | Keep frost-free; tolerates brief cool spells but rots if cold and wet |
| Propagation | Cuttings of stem segments; also seed |
| Toxicity | Generally regarded as non-toxic; the stems are even eaten in parts of its range |
Caralluma europaea is a low, mat-forming stapeliad succulent from the Mediterranean fringe of North Africa and southern Europe. It creeps along the ground in dense clumps of four-angled, greyish-green stems and produces tight clusters of small, five-pointed star flowers that are yellowish and boldly banded with maroon or purple. Like other members of its group it belongs to the milkweed subfamily (Asclepiadoideae) of the Apocynaceae, and its blooms are pollinated by flies drawn to their faintly unpleasant scent. Modern treatments generally place the species in the genus Apteranthes, as Apteranthes europaea.
Description
Caralluma europaea forms spreading, cushion-like mats of short, erect to sprawling stems, each roughly finger-thick and squared-off into four low, toothed angles. The stems are grey-green, often flushed with purple or reddish tones in strong sun, and carry only tiny, quickly-shed rudimentary leaves — the plant photosynthesises through its stems in the manner typical of stapeliads.
The flowers appear in dense clusters near the stem tips. Each is a small, flat, five-lobed star, dirty white to greenish-yellow and crossed by transverse bands of maroon, brown or purple, giving a strongly patterned look. As with its relatives the blooms are fly-pollinated and emit a faint carrion-like odour to attract their insect visitors.
Distribution and habitat
The species is native to the arid Mediterranean fringe, ranging across North Africa from Morocco east to Egypt — and on into the Sinai and western Jordan — while in Europe it is confined to south-eastern Spain (the provinces of Almería and Murcia) and the Italian islands of Lampedusa and Linosa. It is the only stapeliad that occurs naturally in Europe, which is reflected in its name.
In the wild it grows in dry, sunny, open ground: rocky slopes, gravelly flats and coastal scrub, often tucked among stones or at the base of low shrubs that give it a little shelter. It is adapted to hot, dry summers and mild, wetter winters.
Cultivation
Caralluma europaea is grown much as other stapeliads are, and the same cautions apply: it resents sitting wet, and rot is the main risk. Plant it in a very open, mostly mineral mix in a wide, shallow pot that suits its creeping habit, and give it bright light or full sun to keep the stems compact and well-coloured.
Water when the mix has dried during the warm growing season, then ease off as temperatures fall; through winter keep the plant cool and almost completely dry. Good airflow and warmth help prevent the soft black rot that can run through a clump quickly if conditions stay damp. See Watering and Repotting for general technique.
Propagation
The easiest method is by cuttings: a healthy stem segment detached at a node will root readily once its cut surface has been left to dry and callus for a few days, then set on a barely-moist gritty surface. Established clumps naturally offset and spread, so divisions can be lifted with a few roots attached. The species can also be raised from seed, which — as in many stapeliads — is often produced in paired, horn-like follicles carrying tufted, wind-borne seeds. See Propagation — cuttings for a full walkthrough.
Common problems
- Rot — the usual cause of loss, from overwatering, a slow-draining mix or cold damp conditions; affected stems turn soft and blacken. Remove clean segments promptly and re-root them.
- Etiolation — too little light makes the stems thin, stretched and pale, losing their neat compact form.
- Pests — mealybugs (white fluff in the stem angles and among the roots) are the most frequent nuisance; watch also for root mealybug and aphids on the flower clusters.
See also
- Caralluma — the genus overview
- Stapeliad — carrion-flower succulents of the Apocynaceae
- Soil and potting mix · Watering · Propagation — cuttings · Propagation — seed